Winding devices are proposed in the prior art to wind and tighten shoestrings of boots used for skiing, snowboarding, skating, and the like by rotating a handle (circular knob) (patent documents 1 to 5).
There is a need for snowboard boots or the like that allow the shoestring tightening degree to be separately adjusted at the instep of the shoe body and the portion above the ankle. In order to tighten each portion of such a dual-adjustment shoestring, two winding devices need to be coupled to the shoe in the winding device of the above patent documents.
Thus, a tightening device that allows the dual-adjustment shoestring to be separately tightened with a single tightening device has been proposed (patent documents 6 to 9).
However, in the winding device of patent document 6, rotation shafts of two winding units are not coaxially arranged. This enlarges the entire device.
In the winding device of patent document 7, a pulley is pressed by a handle to control the winding of the shoestrings. Thus, when winding different portions of a shoestring, it is difficult to recognize the actuation state of each winding device.
In the tightening devices of patent documents 8 and 9, gears are formed above and below a handle, and the upper and lower gears are driven. In this case, the handle needs to be rotated while making sure that the handle is pressed against the gear.
Further, in the winding devices of patent documents 8 and 9, when such a dial is weakly pressed, the dial may rotate freely. In such a case, the shoestring tightening degree cannot be smoothly adjusted.